A plurality of types of two-dimensional matrix codes, also referred to as QR (Quick Response) codes, exist and the quantity of data capable of being encoded in the form of a QR code depends on the size of said QR code. The QR code is a two-dimensional code, and its size is expressed in the form of a product of two numbers of pixels, each number corresponding to a respective dimension. The larger the size of the matrix code, the greater the quantity of encoded data. In other words, the larger the size of the matrix code, the greater the quantity of data sent via the display of said matrix code to the equipment provided with the reading unit.
The screen is disposed in a plane comprising a horizontal direction and a vertical direction and has a predetermined resolution, i.e. a maximum number of pixels displayable in the horizontal direction multiplied by a maximum number of pixels displayable in the vertical direction. The size of the matrix code is then limited by the resolution of the screen of the display device, since it must be less than this resolution of the screen so that the matrix code can be displayed on the screen.
Furthermore, the resolution is generally variable from one display device to another, and when the same matrix code must be displayable on different display devices having different resolution values, the type of matrix code chosen to send the data will necessarily have a size less than the lowest resolution among said display devices. It will then generally be necessary to display a large number of matrix codes successively in order to send all the data to the equipment provided with the reading unit.